#include <iostream>
#include <vector>
#include<array>


int main() {
	using namespace std;
	double a1[4] = { 1.2, 2.4, 3.6, 4.8 };

	// c++98 STL
	vector<double> a2(4);
	a2[0] = 1.0 / 3.0;
	a2[1] = 1.0 / 5.0;
	a2[2] = 1.0 / 7.0;
	a2[3] = 1.0 / 9.0;

	array<double, 4> a3 = { 3.14, 2.72, 1.62, 1.14 };
	array<double, 4> a4;
	a4 = a3;
	// use array notation
	cout << "a1[2]: " << a1[2] << " at " << &a1[2] << endl;
	cout << "a2[2]: " << a2[2] << " at " << &a2[2] << endl;
	cout << "a3[2]: " << a3[2] << " at " << &a3[2] << endl;
	cout << "a4[2]: " << a4[2] << " at " << &a4[2] << endl;
	// misdeed
	//a1[-2] = 20.2;
	//cout << "a1[-2]" << a1[-2] << " at " << &a1[-2] << endl;
	//cout << "a3[-2]" << a3[-2] << " at " << &a3[-2] << endl;
	//cout << "a4[-2]" << a4[-2] << " at " << &a4[-2] << endl;
	return 0;

}